Collagenase-3 is a matrix metalloprotease that is associated with diseases such as cancer and osteoarthritis. Collagenase 3 degrades type II collagen very efficiently in the joint and inhibitors of this enzyme have been effective at preventing cartilage degradation in ex vivo and in vivo models of osteoarthritis. Recently we discovered novel substrates for collagenase 3 that are highly selective for this enzyme using substrate mapping on protein expression libraries in phage lambda (phage display). One goal is to use this knowledge to develop a "assay" kit that can measure collagenase 3 activity directly in biological fluids. We will develop this kit to include two techniques: fluorescence substrates that are selective for collagenase 3 and neo-epitope antibodies to the cleavage products of collagenase 3. This "assay" kit can then be used to follow disease progression in osteoarthritis, and potentially follow cancer progression, by assessing collagenase 3 activity as a biological marker. PROPOSED COMMERCIAL APPLICATION: NOT AVAILABLE